Please answer the following questions:

1. For a random sample of 60 overweight men, the mean of the number of pounds that they were overweight was 31. The standard deviation of the population is 3.8 pounds. Use a graphing calculator and round the final answers to one decimal place.

• Find the 95% confidence interval of the mean of these pounds.

2. A sociologist found that in a sample of 57 retired men, the average number of jobs they had during their lifetimes was 7.3. The population standard deviation is 2.1. Use a graphing calculator and round the answers to one decimal place.

• Find the 95% confidence interval of the mean number of jobs.

3. If the variance of the water temperature in a lake is 25 , how many days should the researcher select to measure the temperature to estimate the true mean within 2 with 90% confidence? Round the intermediate calculations to two decimal places and round up your final answer to the next whole number.

• The researcher needs a sample of at least ___ days.

4. For a certain group of individuals, the average heart rate is 73 beats per minute. Assume the variable is normally distributed and the standard deviation is 2 beats per minute. If a subject is selected at random, find the probability that the person has the following heart rate. Use a graphing calculator. Round the answers to four decimal places.

• Less than 76 beats per minute.

5. Find p and q. Round your answers to three decimal places. n=61 and X=23

6. One day, a poll appeared on a certain website. It asked "Do you believe that rain can soothe the heart and cleanse the mind?" Unsurprisingly, 70% of 531 answers were "Yes".

Calculate the margin of error for this poll. Round the percentage to one decimal place. Do not round intermediate steps.

• If 531 people were asked that question and 70% of them replied "Yes", the margin of error is ___ %.

7. A survey was conducted to find if modern young people want to have many children. 593 young men were asked if they want to have more than one child. 36% of them answered "Yes".

Calculate the margin of error for this survey. Round the percentage to one decimal place. Do not round intermediate steps.

• If 36% of 593 young men want to have more than one child, the margin of error is ___ %.

8. In a recent year, 6% of cars sold had a manual transmission. A random sample of college students who owned cars revealed the following: out of 124 cars, 27 had manual transmissions. Estimate the proportion of college students who drive cars with manual transmissions with 95% confidence. Round intermediate and final answers to at least three decimal places.

9. In a random sample of 190 people, 142 said that they watched educational television. Find the 95% confidence interval of the true proportion of people who watched educational television. Round the answers to at least three decimal places.

10. In a recent year, a study found that 76% of adults ages 18-29 had internet access at home. A researcher wanted to estimate the proportion of undergraduate college students(18 - 29 years) withaccess, so she randomly sampled 184 undergraduates and found that 159 had access. Estimate the true proportion with 95% confidence. Round intermediate answers to five decimal places. Round your final answer to one decimal place.

• ___%

11. Fear of the dark is quite common among children. However, what about adults? One polling agency released the results of a survey that asked people over 40 years old if they keep the lights on at night. Among 200 respondents, 33% indeed leave the light on when going to sleep.

• Calculate the margin of error for this survey. Round the percentage to one decimal place. Do not round intermediate steps. If 33% of 200 respondents keep the lights on at night, the margin of error is ___ %.

12. Suppose that the results of a survey show that 45% of people consider summer as their favorite season. How many people should be surveyed in order to have a margin of error of 6%? Round up to the nearest whole number, if necessary.

• In order to have a margin of error of 6%, ___ people should be surveyed.

13. According to the results of a survey, 39% of 140 people indicated that American football is their favorite sport. Assuming that the percentage remains the same, how many more people should be surveyed to have a margin of error of 6%? Round up to the nearest whole number, if necessary.

• In order to have a margin of error of 6%, you need to survey ___ more people.